Transports.h

#ifndef TRANSPORTS_H__
#define TRANSPORTS_H__

#include <thread>
#include <mutex>
#include <condition_variable>
#include <functional>
#include <map>
#include <vector>
#include <queue>
#include <string>
#include <memory>
#include <atomic>
#include <boost/asio.hpp>
#include "TransportSession.h"
#include "NTCPSession.h"
#include "SSU.h"
#include "RouterInfo.h"
#include "I2NPProtocol.h"
#include "Identity.h"

namespace i2p
{
namespace transport
{
	class DHKeysPairSupplier
	{
		public:

			DHKeysPairSupplier (int size);
			~DHKeysPairSupplier ();
			void Start ();
			void Stop ();
			std::shared_ptr<i2p::crypto::DHKeys> Acquire ();
			void Return (std::shared_ptr<i2p::crypto::DHKeys> pair);

		private:

			void Run ();
			void CreateDHKeysPairs (int num);

		private:

			const int m_QueueSize;
			std::queue<std::shared_ptr<i2p::crypto::DHKeys> > m_Queue;

			bool m_IsRunning;
			std::thread * m_Thread;	
			std::condition_variable m_Acquired;
			std::mutex m_AcquiredMutex;
	};

	struct Peer
	{
		int numAttempts;
		std::shared_ptr<const i2p::data::RouterInfo> router;
		std::list<std::shared_ptr<TransportSession> > sessions;
		uint64_t creationTime;
		std::vector<std::shared_ptr<i2p::I2NPMessage> > delayedMessages;

		void Done ()
		{
			for (auto it: sessions)
				it->Done ();
		}	
	};	
	
	const size_t SESSION_CREATION_TIMEOUT = 10; // in seconds
	const uint32_t LOW_BANDWIDTH_LIMIT = 32*1024; // 32KBs
	class Transports
	{
		public:

			Transports ();
			~Transports ();

			void Start ();
			void Stop ();
			
			boost::asio::io_service& GetService () { return m_Service; };
			std::shared_ptr<i2p::crypto::DHKeys> GetNextDHKeysPair ();	
			void ReuseDHKeysPair (std::shared_ptr<i2p::crypto::DHKeys> pair);

			void SendMessage (const i2p::data::IdentHash& ident, std::shared_ptr<i2p::I2NPMessage> msg);
			void SendMessages (const i2p::data::IdentHash& ident, const std::vector<std::shared_ptr<i2p::I2NPMessage> >& msgs);
			void CloseSession (std::shared_ptr<const i2p::data::RouterInfo> router);

			void PeerConnected (std::shared_ptr<TransportSession> session);
			void PeerDisconnected (std::shared_ptr<TransportSession> session);
			bool IsConnected (const i2p::data::IdentHash& ident) const;
			
			void UpdateSentBytes (uint64_t numBytes) { m_TotalSentBytes += numBytes; };
			void UpdateReceivedBytes (uint64_t numBytes) { m_TotalReceivedBytes += numBytes; };
			uint64_t GetTotalSentBytes () const { return m_TotalSentBytes; };
			uint64_t GetTotalReceivedBytes () const { return m_TotalReceivedBytes; };		
			uint32_t GetInBandwidth () const { return m_InBandwidth; }; // bytes per second
			uint32_t GetOutBandwidth () const { return m_OutBandwidth; }; // bytes per second
			bool IsBandwidthExceeded () const;
			size_t GetNumPeers () const { return m_Peers.size (); };
			std::shared_ptr<const i2p::data::RouterInfo> GetRandomPeer () const;

			void PeerTest ();
			
		private:

			void Run ();
			void RequestComplete (std::shared_ptr<const i2p::data::RouterInfo> r, const i2p::data::IdentHash& ident);
			void HandleRequestComplete (std::shared_ptr<const i2p::data::RouterInfo> r, const i2p::data::IdentHash& ident);
			void PostMessages (i2p::data::IdentHash ident, std::vector<std::shared_ptr<i2p::I2NPMessage> > msgs);
			void PostCloseSession (std::shared_ptr<const i2p::data::RouterInfo> router);
			bool ConnectToPeer (const i2p::data::IdentHash& ident, Peer& peer);
			void HandlePeerCleanupTimer (const boost::system::error_code& ecode);			

			void NTCPResolve (const std::string& addr, const i2p::data::IdentHash& ident);
			void HandleNTCPResolve (const boost::system::error_code& ecode, boost::asio::ip::tcp::resolver::iterator it,
 				i2p::data::IdentHash ident, std::shared_ptr<boost::asio::ip::tcp::resolver> resolver);

			void UpdateBandwidth ();
			void DetectExternalIP ();
			
		private:

			bool m_IsRunning;
			std::thread * m_Thread;	
			boost::asio::io_service m_Service;
			boost::asio::io_service::work m_Work;
			boost::asio::deadline_timer m_PeerCleanupTimer;

			NTCPServer * m_NTCPServer;
			SSUServer * m_SSUServer;
			std::map<i2p::data::IdentHash, Peer> m_Peers;
			
			DHKeysPairSupplier m_DHKeysPairSupplier;

			std::atomic<uint64_t> m_TotalSentBytes, m_TotalReceivedBytes;
			uint32_t m_InBandwidth, m_OutBandwidth;
			uint64_t m_LastInBandwidthUpdateBytes, m_LastOutBandwidthUpdateBytes;	
			uint64_t m_LastBandwidthUpdateTime;		

		public:

			// for HTTP only
			const NTCPServer * GetNTCPServer () const { return m_NTCPServer; };
			const SSUServer * GetSSUServer () const { return m_SSUServer; };
			const decltype(m_Peers)& GetPeers () const { return m_Peers; };
	};	

	extern Transports transports;
}	
}

#endif